A Highly Diastereoselective Epoxidation of N-Boc 2-Alkenyloxazolidines: Application in Asymmetric Synthesis

Treatment of N-Boc Derivatives of β-Amino Alcohols with N,N-Diethylaminosulfur Trifluoride Leads to Chiral Oxazolidinones: An Unexpected Intramolecular Cyclization

“…For example, Agami et al found that reaction of 13 with p-toluenesulfonyl chloride at 0 ∞C afforded the expected tosylate derivative. Oxazolidinone 14 could then be obtained by heating at 60 ∞C, 5 or upon stirring for 3 days at room temperature 4. Similarly, Curran et al found that cyclization of the o-tosylate derivative of 5 to 2-oxazolidinone 6 required standing at room temperature for a week 3.…”

Synthesis of functionalised dithiocarbamates via N-(1-benzotriazolylalkyl)dithiocarbamates

“…34 The preparation of compounds 2 via cyclization of methyl β-hydroxyalkyldithiocarbamates 11 upon treatment with mesyl chloride in pyridine (Scheme 2, Route v) 24 and via cyclization of 2-alkylaminoethanethiols 12 with thiophosgene in the presence of a base (Route vi) 33 have also been reported. The alkylation of thiazolidine-2-thiones 13 with alkyl halides in the presence of a base gives 2-alkylthiothiazoles 14 (Scheme 2, Route ix).…”

The Use of N‐Boc‐1,3‐Oxazolidines as Chiral Auxiliaries in Asymmetric Synthesis

“…In 1995 [41] we reported a convenient synthesis of N-Boc-2-alkenyloxazolidines, and their diastereoselective epoxidation. Condensation of the enals 73 with (R)-phenylglycinol gives the α,β-unsaturated imino alcohol 74, and treatment of this with Boc 2 O produces an acyliminium ion that irreversibly cyclizes to give cis 2-alkenyloxazolidines 75 with high stereoselectivity.…”