ABSTRACT
The total synthesis of a typical 11-hydroxylated steroid, (+/-)-11 alpha-hydroxyprogesterone, was achieved by picric acid-catalyzed tricyclization of a polyunsaturated epoxide appropriately substituted with ketal, hydroxyl, and acetylenic units. This epoxide was prepared by a multistage sequence featuring two successive alkylations of intermediary, monocyclic sulfones. The first sulfone intermediate was obtained by means of a short sequence starting from levulinic acid and diethyl succinate and involving a selective cyclization reaction.
Subject(s)
Hydroxyprogesterones/chemical synthesis , Cyclization , Epoxy CompoundsABSTRACT
Through the use of (Cp(2)TiH)(x) or (Cp(2)Ti)(1-2), in which Cp is C(5)H(5) (cyclopentadienyl ligand), it is possible to effect not only the previously known direct reduction of aldehydes and esters to alkanes but also the one-step conversion to alkane of amides derived from selected primary aromatic amines.
Subject(s)
Deoxyribonucleotides/isolation & purification , Oligonucleotides/isolation & purification , Ribonucleotides/isolation & purification , Chromatography, Ion Exchange , Deoxyribonucleotides/analysis , Evaluation Studies as Topic , Methods , Oligonucleotides/analysis , Ribonucleotides/analysis , Silicon Dioxide , Spectrophotometry, Ultraviolet , Time FactorsSubject(s)
Antiviral Agents , Magnetic Resonance Spectroscopy , Pyrans , Aldehydes , Carboxylic Acids , Chemical Phenomena , Chemistry , Molecular ConformationSubject(s)
Sterols/chemical synthesis , Chemical Phenomena , Chemistry , Cyclization , Isomerism , Norsteroids/chemical synthesis , Oxides , Squalene , TritiumSubject(s)
Metals , Nitrogen Fixation , Oxidoreductases , Iron , Models, Chemical , Molybdenum , TitaniumABSTRACT
The high-yield, stereoselective conversion of geraniol (3,7-dimethyl-trans-2,6-octadien-1-ol) to the insect juvenile hormone, methyl 12,14-dihomojuvenate (methyl cis-10-epoxy-3,11-dimethyl-7-ethyl-trans, trans-2,6-tridecadienoate), has been performed by means of a nine-step route that avoids chromatography of intermediates.
