ABSTRACT
A facile synthesis of marine natural product smenodiol has been achieved in 23.2% overall yield within 8 steps from readily available starting materials, which facilitates a concise synthesis of the marine natural product (-)-pelorol by employing a TMSOTf-mediated Friedel-Crafts reaction with a methyl ester in the aryl as the key step.
Subject(s)
Biological Products , Sesquiterpenes , EstersABSTRACT
A step-economical synthesis of (-)-15-oxopuupehenol from cheap and readily available (+)-sclarelide is achieved with 20.3% overall yield in 9 steps. The key features of this synthetic mythology include a palladium catalyzed tandem carbine migratory insertion reaction to construct the key skeleton, a DDQ-mediated isomerization/oxidation of allyl alcohol to afford α, ß-unsaturated ketone, and a NaOH-induced intramolecular Michael addition followed by acetonide deprotection to give (-)-15-oxopuupehenol.
Subject(s)
Biological Products , Diterpenes , Stereoisomerism , CatalysisABSTRACT
An expeditious access to marine natural products (+)-strongylin A and corallidictyal D is described. A TFA/Et3SiH-induced reductive isomerization of enols I to alkenyl benzenes II followed by a selectivity-controlled cyclization in the presence of HCl and BF3·Et2O affords benzofuran III and benzopyran IV, respectively. The applicability of this HCl-induced cyclization is showcased by a regio- and stereoselective synthesis of corallidictyal D, while BF3·Et2O-promoted cyclization posterior to rearrangement of an alkenyl benzene provides a regioselectively different benzopyran, (+)-strongylin A.
Subject(s)
Benzene , Biological Products , Cyclization , BenzopyransABSTRACT
C2-arylation of N-acyl pyrroles with aryl halides is developed for the first time using Pd(PPh3)4 as a catalyst in combination with Ag2CO3 under air, which allowed the application of a good compatibility catalytic system. This protocol provides a straightforward method for the preparation of valuable arylated pyrroles in moderate to good yields under the standard conditions with good substrate tolerance. Interestingly, while N-benzoyl pyrroles reacted well, the use of substrates with a thiophene or furan ring indicated that the thiophene and furan rings are more reactive than pyrrole for the present catalytic system.
ABSTRACT
Inulavosin, a natural melanogenesis inhibitor, has been synthesized smoothly from readily available and inexpensive starting materials by using a Ga(OTf)3-catalyzed room temperature hetero Diels-Alder dimerization of salicyl alcohol derivative and a regioselective phenol monobromination as the key steps.
Subject(s)
Benzyl Alcohols/chemistry , Cycloaddition Reaction , Flavonoids/chemical synthesis , Biological Products/chemical synthesis , Catalysis , Dimerization , Flavonoids/pharmacology , Halogenation , Melanins/antagonists & inhibitors , Octamer Transcription Factor-3ABSTRACT
BACKGROUND: Early embryonic developmental arrest is the most commonly understudied adverse outcome of pregnancy. The relevance of intrauterine infection to spontaneous embryonic death is rarely studied and remains unclear. This study aimed to investigate the relationship between intrauterine bacterial infection and early embryonic developmental arrest. METHODS: Embryonic chorion tissue and uterine swabs for bacterial detection were obtained from 33 patients who underwent artificial abortion (control group) and from 45 patients who displayed early embryonic developmental arrest (trial group). RESULTS: Intrauterine bacterial infection was discovered in both groups. The infection rate was 24.44% (11/45) in the early embryonic developmental arrest group and 9.09% (3/33) in the artificial abortion group. Classification analysis revealed that the highest detection rate for Micrococcus luteus in the early embryonic developmental arrest group was 13.33% (6/45), and none was detected in the artificial abortion group. M. luteus infection was significantly different between the groups (P < 0.05 as shown by Fisher's exact test). In addition, no correlation was found between intrauterine bacterial infection and history of early embryonic developmental arrest. CONCLUSIONS: M. luteus infection is related to early embryonic developmental arrest and might be one of its causative factors.
