6'-Oxa Analogs of S-Adenosylhomocysteine.

S-Adenosylmethionine (AdoMet) is a ubiquitous cofactor in biomethylations and, in that role, becomes S-adenosylhomocysteine (AdoHcy), which serves as a biofeedback inhibitor of the methylation process. In seeking to avail unexplored structural variations of AdoHcy for biological studies, its 6'-oxa analog and two corresponding carbocyclic nucleosides (based on aristeromycin and neplanocin) have been prepared via common convergent syntheses.