Enantioselective total synthesis of valeriananoids A-C.

[reaction: see text] The first enantioselective total synthesis of valeriananoids A-C (-)-1-3 is reported starting from the readily available monoterpene (R)-carvone, employing a tandem intermolecular Michael addition-intramolecular Michael addition-alkylation sequence and an electron-transfer-mediated 6-endo-trig cyclization as key steps.

Synthetic approaches to guanacastepenes. Enantiospecific syntheses of BC and AB ring systems of guanacastepenes and rameswaralide.

[reaction: see text] A simple and efficient approach for the BC and AB ring systems of the novel diterpenes guanacastepenes and rameswaralide starting from the readily and abundantly available monoterpene (R)-carvone employing RCM reaction as the key step is described.

Enantiospecific first total synthesis and assignment of absolute configuration of the sesquiterpene (-)-cucumin H.

The first total synthesis of the sesquiterpene (-)-cucumin H, a linear triquinane isolated from Macrocystidia cucumis, has been accomplished starting from (R)-limonene employing two different cyclopentannulation methodologies, which in addition to confirming the structure also established the absolute configuration of the natural product. [reaction: see text]

An enantiospecific approach to tricyclic sesquiterpenes mayurone and thujopsenes.

An enantiospecific approach to mayurone and thujopsenes, sesquiterpenes containing three contiguous quaternary carbon atoms, starting from (R)-carvone (8), is described. (S)-3,4,4-Trimethylcarvone (7), obtained from (R)-carvone, was transformed into the bicyclo[2.2.2]octanone 13 via regioselective intramolecular alkylation of the allyl bromide 11. Regioselective ozonolysis and Criegee fragmentation of the bicyclic ketone 13 furnished the keto ester 14. Reductive deoxygenation followed by one-carbon homologation transformed the keto ester 19 into the ester 6. Intramolecular cyclopropanation of the diazo ketone 25, derived from the acid 5, furnished (-)-dihydromayurone (4), thus constituting a formal enantiospecific synthesis of mayurone and thujopsenes.

Enantiospecific total synthesis of (-)-4-thiocyanatoneopupukeanane.

Enantiospecific synthesis of the natural enantiomer of the marine sesquiterpene (-)-4-thiocyanatoneopupukeanane (6) is described. The bicyclo[2.2.2]octanecarboxylate 14, obtained from (R)-carvone via Michael-Michael reaction, was transformed into neopupukeananedione 12 by employing rhodium acetate catalyzed intramolecular C-H insertion of the diazo ketones 16 or 19 as the key reaction. Regioselective deoxygenation of the C-2 ketone transformed the dione 12 into neopupukean-4-one 10. Alternately, the keto ester 18 was also transformed into neopupukean-4-one 10 via regioselective deoxygenation of the ketone in 18 followed by intramolecular rhodium carbenoid C-H insertion of the diazo ketone 31. Finally, neopupukean-4-one 10 was transformed into (-)-4-thiocyanatoneopupukeanane 6 via the alcohol 32 and the mesylate 33.

Clinicohaematological profile of two cases of inhibitors to factor VIII.

Bleeding is a common manifestation of inherited and acquired disorders of haemostasis. Acquired disorders of haemostasis can be of varied etiology like liver disease, DIC, haemorrhagic disease of newborn and inhibitors to coagulation factors. Inhibitors to coagulation factors are an unusual cause of bleeding which can be superimposed on inherited factor deficiencies or sometimes resembles them. The clinical and haematological profile to two cases of factor VIII inhibitors are being presented here, one of which was a known haemophiliac receiving factor VIII therapy and another was a elderly lady with no other apparent underlying disorder. Hence any case of factor VIII deficiency who becomes refractory to factor VIII replacement therapy or those who are detected to have factor deficiency late in life should be investigated for inhibitors.

An unusual case of haemophilia--a case report.

Haemophilia in a female is very rare. We report a case of haemophilia in a female with a male sex chromosome pattern.

How safe are our safe donors?

One of the greatest challenges of transfusion medicine is the prevention of transmission of infectious diseases through blood transfusion. The aim of this study is to present the current status of transfusion transmitted diseases among healthy unpaid blood donors so as to heighten the awareness of the complications of blood transfusion and make usmore vigilant with regard to the specifics of blood collection and testing as well as judicious use of blood. 8617 donors donated at St. Johns Medical College Hospital Blood bank from 1st. September 1997 to 31st August 1998. The tests done on all units included testing for HIV 1&2, HBsAg, HCV, VDRL and malarial parasites. The seropositivity among donors for HIV was 0.44%, for HBsAg 1.86%, for HCV 1.02% and for VDRL 1.6% No MP Positives were picked up in the study period. The focus has been on HIV so far. We have found the magnitude of hepatitis to be far more than that of HIV. Hence testing for HCV routinely is recommended.