4-Chloro-2-trimethylstannyl-1-butene

4-Chloro-2-trimethylstannyl-1-butene is a precursor of several bifunctional reagents, which have been employed to effect synthetically useful methylenecyclopentane annulation sequences.

4-chloro-2-trimethylstannyl-1-butene is readily prepared from the commercially available butynol (1). Regioselective addition of Me3SnCu.Me2S (see Trimethylstannylcopper-Dimethyl Sulfide) to (1) provides 3-trimethylstannyl-3-buten-1-ol (2), which upon reaction with Ph3P-CCl4 in the presence of Et3N affords (3) (eq 1). This preparative sequence can be carried out on a reasonably large scale (0.2 mol) and produces overall yields of about 50%.