ChemInform Abstract: Enantiomeric Syntheses of (6R,7R)‐ and (6S,7S)‐trans‐ and cis‐Laurediol.

Are Alkyne Reductions Chemo-, Regio-, and Stereoselective Enough To Provide Pure (Z)-Olefins in Polyfunctionalized Bioactive Molecules?

“…Besides (Z)-or (E)-allylic functions, 314,321,379,380 cyclic double bond, 336 isolated (E)- 361,381 or (Z)- 332,356 double bond, conjugated (E)-olefin, 333,357,372 or a terminal alkene, 314 the semireduction of isolated alkynes and/or poly skipped diynes also showed a high chemoselectivity in the presence of (Z,Z)-bis-allylic systems, 361,379 but it is also respectful of conjugated 1,3-diene ((E,Z)-diene 307,320,360 or (E,E)diene 338,378 ) and conjugated (E,E,E)-triene. 331 Thus, this methodology is widely used in the synthesis of natural products such as leukotriene B4, 355,382 HETEs, 199,323 pheromones (identification in female gametes of Analipus japonicus), 329 carotenoids.…”

Progress in the Chemistry of Organic Natural Products 102

“…To date, only 13 acetogenins containing seven-membered cyclic ethers (784)(785)(786)(787)(788)(789)(790)(791)(792)(793)(794)(795)(796) have been obtained from Laurencia species or their grazers. Their oxepane ring is formed in all cases by etherification between C-7 and C-12.…”