Rearrangement of Homoallylic Alcohols Induced by DAST

Abstract

[reaction: see text] Treatment of beta,gamma-unsaturated monoprotected 1,2-diols with diethylaminosulfur trifluoride (DAST) allows the stereoselective formation of beta,gamma-unsaturated aldehydes in good yields and with a good transfer of chirality.

Triphosgene–Amine Base Promoted Chlorination of Unactivated Aliphatic Alcohols

“…Alcohol 8e 31 (324 mg, 2.00 mmol) was utilized along with pyridine (0.32 mL, 4.00 mmol) and triphosgene (297 mg, 1.00 mmol) to produce 9e in 94% yield as a colorless oil (340 mg, 1.88 mmol). The purified product was eluted with 100% pentane.…”

Morpholinosulfur Trifluoride (Morph‐DAST)‐Mediated Rearrangement in the Fluorination of Cyclic α,α‐Dialkoxy Ketones toward 1,2‐Dialkoxy‐1,2‐difluorinated Compounds

“…[8] Other examples consist of the neighbouring group participation of the indole nucleus in the 3,4-migration of 4-indolyl-3-hydroxypiperidines, [9] the ring expansion of bicyclic epoxy alcohols toward fluorovinyl ethers, [10] the rearrangement of 2-azabicycloA C H T U N G T R E N N U N G [2.2.0]hexan-6-ols to 5-fluoro-2-azabicyclo-[2.1.1]hexanes [11] and the rearrangement of b-methoxy homoallyl alcohols to a,bunsaturated aldehydes. [12] The DAST-mediated 1,2-migrations, 1,4-migrations and 1,6-migrations of the anomeric substituent of saccharides, with or without ring contraction, are of special importance in biological studies of deoxofluorinated analogues of carbohydrates. [13] In contrast to alcohols, rearrangements of ketones have been less investigated.…”