{'fraction_non_alphanumeric': 0.028985507246376812, 'fraction_numerical': 0.011594202898550725, 'mean_word_length': 5.169642857142857, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Asymmetric Synthesis of the Antiviral Diterpene Wickerol A.

Wickerol A (1) is an unusual diterpene with remarkable activity against the H1N1 influenza virus. Its tetracyclic skeleton contains three quaternary carbons and is marked by several syn-pentane interactions which force a six-membered ring into a twist-boat conformation. We present an asymmetric synthesis of wickerol A (1) that is based on a Jung Diels-Alder reaction, an intramolecular alkylation to complete the 6-5-6-6 ring system, and a conjugate addition, all of which overcome considerable steric strain. During the synthesis, we isolated an unexpected cyclopropane that presumably stems from a carbonium ion intermediate.