Fig. 1. 1H in Dihydro-furanones from Hyptis species: Chemical correlations and DFT-NMR/ECD calculations for stereochemical assignments

Fig. 1. 1H NMR spectral sections of peracetylated montecofuranolide (2). (A) Simulated spectrum using DFT 3J of peracetyl-5′-epi-synrotolide (5) in gas H,H phase with chemical shifts of the experimental spectrum of compound 2 and coupling constants of monticolide A (6) for J ′ ′ 3 -4 proS = 8.7 Hz, J ′ ′ 3 -4 proR = 4 Hz to simulate the multiplicity for H-4′. (B) Fully simulated spectrum obtained by iteration of chemical shifts, 3J, and linewidths of compound 2. (C) ExperiH,H mental spectrum in CDCl3 (400 MHz).