Fluoride-Mediated Elimination of Allyl Sulfones: Application to the Synthesis of a 2,4-Dimethyl-A-ring Vitamin D₃ Analogue

Abstract

A coupling strategy for the synthesis of 2,4-dimethyl-1α,25(OH)(2)D(3) is achieved which involves methylation of a pro-A ring vinyl sulfone and in situ traping of the allyl sulfonyl anion with a CD ring allyl chloride. TBAF-promoted 1,2-eliminative desulfonylation and concomitant silyl ether deprotection gives the vitamin D(3) analogue.

Site-Selective Conversion of Azido Groups at Carbonyl α-Positions to Diazo Groups in Diazido and Triazido Compounds

“…For the second step, the reaction should be conducted with weaker bases because alkoxides have been reported to destroy benzylic azides . Among them, TBAF (tetrabutylammonium fluoride) as a base reagent was observed to generate a similar yield to entry 2 (entry 3). Additional water to examine the possible pathway through aldehydes by hydrolysis did not improve the result (entry 4).…”

A Green Synthesis of Highly Functionalized 3‐amino‐2‐phenylsulfonyl‐1‐alkyl/aryl‐1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐diones and Their Reduction and Photophysical Studies

“…There are numerous examples of desulfonylation via Julia‐type elimination. Sodium and magnesium metals have been used for the various reductively desulfonylated reactions where they act as a source of reductant . However, it was not envisioned that the reductive nature of sodium or magnesium metal could be used for the deprotection of the phenylsulfonyl group, and 4a was cut into two parts that is 2 and 7 .…”

New frontiers in the transition-metal-free synthesis of heterocycles from alkynoates: an overview and current status

“…After performing several mechanistic experiments and in line with the literature reports, the authors proposed a possible reaction mechanism which starts with the coordination of arydiazonium cation 167 with DABSO to form the complex 170 via electrostatic interaction. 165 Homolytic cleavage of the N-S bond 166 Due to the widespread applications of sulfone functionalities in organic and medicinal chemistry, [168][169][170][171][172][173][174][175][176][177] the synthesis of organic molecules with these groups remained an attractive pursuit for many research groups. Recently, Wang and coworkers 178 developed a new metal-free approach to construct structurally diverse 3-sulfonated coumarins 180 (Scheme 42).…”