Correction to “Tin-Free Access to the ABC Core of the Calyciphylline A

Addition/Correction Cite This: Org. Lett. XXXX, XXX, XXX−XXX

pubs.acs.org/OrgLett

Correction to “Tin-Free Access to the ABC Core of the Calyciphylline A Alkaloids and Unexpected Formation of a D‑Ring-Contracted Tetracyclic Core” Alberto M. Lopez, Ahmad A. Ibrahim, Gregory J. Rosenhauer, Hansamali S. Sirinimal, and Jennifer L. Stockdill* Org. Lett. 2018, 20 (8), 2216−2219. DOI: 10.1021/acs.orglett.8b00544

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he following corrections were made in Scheme 6 and the first sentence of the paragraph describing it: (1) a missing methyl group was added to 19; (2) step 1 (DIBAL-H, THF, −78 °C) was removed from ent-6 → 19; (3) “2 steps” next to “84% yield” was deleted for ent-6 → 19; (4) the time for PPh3, THF is 34 h; the time for LAH is 1.5 h for ent-6 → 19. Scheme 6. Synthesis of ABC Core for Knoevenagel Approach

The text for the paragraph above Scheme 6 was changed to read as follows: At this point, we directed our attention to the synthesis of cyclization precursor ent-5c, derived from known alkynyl azide 7c...” and “Assembly of N-chloroamine ent-5c began with an aza-Wittig reaction of lactol ent-6 with azide 7c...”. The corrected Scheme 6 is shown.

Received: May 1, 2018

© XXXX American Chemical Society

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DOI: 10.1021/acs.orglett.8b01384 Org. Lett. XXXX, XXX, XXX−XXX