John Francis Lambert

Fast atom bombardment-promoted reductive ring opening of 1,2-benzisothiazoles

Abstract Fast atom bombardment mass spectral examination of molecules containing a 1,2-benzisothiazole ring, using a thiol reducing agent matrix, promotes reductive ring opening of the benzisothiazole ring, giving an [M+H] + two daltons higher than expected. Measurements using a non-reducing matrix produce the expected [M+H] + . This is a general phenomenon, observed with a number of molecules containing the benzisothiazole ring. The ring-opened structure has been confirmed by chemical synthesis and observed in metabolic studies.

Thermal glycosylations: Reactions of β-cellobiosyl fluoride heptaacetate with tigogenin and its trimethylsilyl ether

Abstract Thermal reaction of β-cellobiosyl fluoride heptaacetate with ticogenin in toluene or o -xylene at 112–142 °C gave ticogenyl β-cellobioside heptaacetate in 69–75% yields with good stereoselectivity. The procedure avoids the use of Lewis acid or traditional glycosidation promotors. The deacetylated product is a hypocholesterolemic and anti-atherosclerosis agent.