Base-promoted intramolecular cyclization of bromoacetylenic alcohol derivatives
摘要:
5-Bromo-2,3-epoxy-4-pentyn-1-ol 6a, the corresponding esters 1a, 2a and the silyl protected form 5a could be intramolecularly cyclized under mildly basic conditions or with a catalytic amount of base. 1-Bromoethynyl-2-hydroxymethyl-cyclopropane 6b and its derivatives 2b and 5b could also be cyclized under the same conditions.
An improved procedure for aldehyde-to-alkyne homologation via 1,1-dibromoalkenes; synthesis of 1-bromoalkynes
摘要:
1,1-Dibromoalkenes, 1-bromoalkynes and alkynes could be obtained in excellent yields by homologation of functionnalized aldehydes through a modified Mc Kelvie-Corey procedure.