SYNTHESIS OF AND CONFORMATIONAL STUDIES ON N-ALKYL-3-THIA-7-AZABICYCLO [3.3.1]NONAN-9-ONES AND DERIVATIVES. A SINGLE CRYSTAL X-RAY DIFFRACTION ANALYSIS OF 2,2,4,4-TETRAMETHYL-6,8-DIPHENYL-3-THIA-7-AZABICYCLO [3.3.1]-NONAN-9-ONE

Abstract

A series of N-alkyl-3-thia-7-azabicyclo[3.3.1]nonan-9-ones and derivatives have been prepared from the reaction of an appropriate 4-thianone, an aldehyde and an amine in a Mannich type condensation. Reduction of the ketones via Wolff-Kishner conditions produced bicyclic systems with the methylene bridging group. Addition of Grignard reagents to the ketones did yield the expected alcohols. Conformational analysis of the systems was performed via diagnosis of the ¹H and ¹³C NMR spectra. A single crystal X-ray diffraction analysis of 2,2,4,4-tetramethyl-6,8-diphenyl-3-thia-7-azabicyclo[3.3.1]nonan-9-one was accomplished and revealed a boat conformer for the nitrogen-containing ring and a chair conformer for the sulfur-containing ring. The ketone crystallized in the triclinic space group P1 (Z=2) with a=6.216 (3), b=10.507 (5), c=15.335 (6) Å, α=86.64 (4), β=86.66 (4), and γ=98.51 (5)° [Vol=986.55 ų].