1-Alkenesulfinyl Chlorides: Synthesis, Characterization, and Some Substitution Reactions
摘要:
A number of 1-alkenyl sulfoxides bearing either a diphenylmethyl (DPM) or a p-methoxybenzyl (PMB) group have been prepared and exposed to the chlorine surrogate SO2Cl2. Through an oxidative fragmentation reaction, a new family of sulfur acid derivatives, 1-alkenesulfinyl chlorides, is generated. They can be characterized by IR spectroscopy before chemical capture with an alcohol. Ethenesulfinyl chloride (2a) and 1-propenesulfinyl chloride (2b), obtained from their corresponding DPM precursor, can be distilled at reduced pressure to afford ca. 90% pure material. NMR chemical shift comparison of various 1-alkenesulfinyl-containing compounds is made. 1-Alkenesulfinylmethyl phenyl(alkyl) ketones (6) can be prepared directly from sulfinyl chlorides 2 although decomposition and/or isomerization is sometimes extensive during purification.
Highly Diastereoselective Intramolecular Diels−Alder Reactions of Furan-Tethered 1-Alkenesulfinic Acid Esters
摘要:
[GRAPHICS]The capture of selected 1-alkenesulfinyl chlorides with furan-tethered alcohols leads to the formation of diene-tethered 1-alkenesulfinate esters, The esters can spontaneously or with Lewis acid treatment undergo an IM DA reaction to form exo adducts with very high diastereoselectivity. Computational predictions using density functional theory indicate the preferred transition state for cyclization and find little preference for the sulfinyl configuration in the products.