UNITED
STATES
SECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C.
20549_____________________



FORM 10-K_____________________



|☒ | ANNUAL
    REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2017                                                                                                                                  
|- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 
| 
|  | OR                                                                                                                                                                                                                                                                    
|  |                                                                                                                                                                                                                                                                       
|☐ | TRANSITION
                                                                      REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM
                                                                      TO
| 
| 



Commission File Number of issuing entity:
001-32867Central Index Key Number of issuing entity: 0001357660STRATS TRUST FOR ALLSTATE CORPORATION SECURITIES, SERIES 2006-3(Exact name of issuing entity as specified in its charter)



Commission File Number of depositor
and sponsor: 001-31818Central Index Key Number of depositor and sponsor: 0001140396SYNTHETIC FIXED-INCOME SECURITIES, INC.(Exact name of depositor and sponsor as specified in its charter)



|New York
(State of incorporation or organization
of the issuing entity)                                         | 26-6115117
(IRS Employer Identification No.)
|--------------------------------------------------------------------------------------------------------------- | --------------------------------------------
|                                                                                                                |                                             
|One Wells Fargo Center
301 S. College Street
Charlotte, North Carolina
(Address of principal executive offices) | 28288
(Zip Code)                            
|                                                                                                                |                                             



SECURITIES REGISTERED PURSUANT
TO SECTION 12(b) OF THE ACT:



|Title of Class                      | Name of  Registered Exchange     
|----------------------------------- | ---------------------------------
|STRATS  Certificates, Series 2006-3 | New York  Stock Exchange (“NYSE”)



SECURITIES REGISTERED PURSUANT
TO SECTION 12(g) OF THE ACT: NONE



Indicate by check mark if the registrant
is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.



☐
Yes ☒ No



Indicate by check mark if the registrant
is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.



☐
Yes ☒ No



Indicate by check mark whether the registrant
(1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding
12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.



☒
Yes ☐ No



Indicate by check mark whether the registrant
has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted
and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such
shorter period that the registrant was required to submit and post such files).



☒
Yes ☐ No



Indicate by check mark if disclosure of
delinquent filers pursuant to Item 405 of Regulation S-K (§ 229.405 of this chapter) is not contained herein, and will not
be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference
in Part III of this Form 10-K or any amendment to this Form 10-K. ☐



Indicate by check mark whether the registrant
is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definition of “large
accelerated filer”, “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange
Act.



|Large accelerated filer ☐ | Accelerated filer ☐ | Non-accelerated filer ☒ | Smaller Reporting Company ☐
|------------------------- | ------------------- | ----------------------- | ---------------------------



Indicate by check mark whether the registrant
is a shell company (as defined in Rule 12b-2 of the Exchange Act).



☐
 Yes ☒  No



State the aggregate market value of the
voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last
sold, or the average bid and asked price of such common equity, as of the last business day of the registrant’s most recently
completed second fiscal quarter.



Not applicable.



DOCUMENTS INCORPORATED BY REFERENCE



List hereunder the following documents if
incorporated by reference and the part of the Form 10-K (e.g., Part I, Part II, etc.) into which the document is incorporated:
(1) Any annual report to security holders; (2) Any proxy information statement; and, (3) Any prospectus filed pursuant to Rule
424(b) or (c) under the Securities Act of 1933. The listed documents should be clearly described for identification purposes (e.g.,
annual report to security holders for fiscal year ended December 24, 1980).



None.
















PART I



The following Items have been omitted in accordance with
General Instruction J to Form 10-K:



Item 1. Business.



Item IA. Risk Factors.



Item 2. Properties.



Item 3. Legal Proceedings.



Item 1B. Unresolved Staff Comments.



Not Applicable.



Item 4. Mine Safety Disclosures.



Not Applicable.



PART II



The following Items have been omitted in accordance with
General Instruction J to Form 10-K:



Item 5. Market for Registrant’s Common Equity,
Related Stockholder Matters and Issuer Purchases of Equity Securities.



Item 6. Selected Financial Data.



Item 7. Management’s Discussion and Analysis
of Financial Condition and Results of Operations.



Item 7A. Quantitative and Qualitative Disclosures
About Market Risk.



Item 8. Financial Statements and Supplementary Data.



Item 9. Changes in and Disagreement with Accountants
on Accounting and Financial Disclosure.



Item 9A. Controls and Procedures.



Item 9B. Other Information.



None.



PART III



The following Items have been omitted in accordance with
General Instruction J to Form 10-K:



Item 10. Directors, Executive Officers and Corporate
Governance.



Item 11. Executive Compensation.



2







Item 12. Security Ownership of Certain Beneficial
Owners and Management and Related Stockholder Matters.



Item 13. Certain Relationships and Related Transactions,
and Director Independence.



Item 14. Principal Accountant Fees and Services.



Substitute information provided in accordance with General
Instruction J to Form 10-K:



Item 1112(b) of Regulation AB. Significant Obligors of Pool
Assets (Financial Information).



The Allstate Corporation, the issuer of
the underlying securities, is subject to the information reporting requirements of the Securities Exchange Act of 1934 (the “Exchange
Act”). For information on The Allstate Corporation please see its periodic and current reports filed with the Securities
and Exchange Commission (the “Commission”) under its Exchange Act file number, 001-11840. The Commission maintains
a site on the World Wide Web at “http://www.sec.gov” at which users can view and download copies of reports, proxy
and information statements and other information filed electronically through the Electronic Data Gathering, Analysis and Retrieval
system, or “EDGAR.” Periodic and current reports and other information required to be filed pursuant to the Exchange
Act by The Allstate Corporation may be accessed on this site. Neither Synthetic Fixed-Income Securities, Inc. nor the Trustee has
participated in the preparation of such reporting documents, or made any due diligence investigation with respect to the information
provided therein. Neither Synthetic Fixed-Income Securities, Inc. nor the Trustee has verified the accuracy or completeness of
such documents or reports. There can be no assurance that events affecting the issuer of the underlying securities or the underlying
securities themselves have not occurred or have not yet been publicly disclosed which would affect the accuracy or completeness
of the publicly available documents described above.



Item 1114(b)(2) of Regulation AB. Credit Enhancement and
Other Support, Except for Certain Derivatives Instruments (Financial Information).



None.



Item 1115(b) of Regulation AB. Certain Derivatives Instruments
(Financial Information).



None.



Item 1117 of Regulation AB. Legal Proceedings.



There are no legal proceedings pending,
or any proceedings known to be contemplated, by governmental authorities against the depositor, the Trustee or the issuing entity,
or any property thereof, that is material to the holders of the Certificates.



Item 1119 of Regulation AB. Affiliations and Certain Relationships
and Related Transactions.



In accordance with the Instruction to Item
1119, affiliations and certain relationships and related transactions are described below in response to this item.



Wells Fargo Bank, National Association (“Wells
Fargo Bank”), as successor to Wachovia Bank, National Association, is the “Swap Counterparty” with respect to
its obligations under the ISDA Master Agreement including the Schedule thereto and a confirmation thereunder, by and among the
Swap Counterparty and the issuing entity, dated as of April 28, 2006.  Wells Fargo Bank is an affiliate of Synthetic
Fixed-Income Securities, Inc., the sponsor of the issuing entity and the depositor of the issuing entity and Wells Fargo Securities,
LLC (formerly known as Wachovia Capital Markets, LLC), who acted as an underwriter of the Certificates issued by the issuing entity.



3







The Trustee is unaffiliated with, but may
have normal banking relationships with, the sponsor, the depositor and their respective affiliates.



Item 1122 of Regulation AB. Compliance with Applicable Servicing
Criteria.



The Trustee has been identified as a party
participating in the servicing function during the reporting period with respect to the pool assets held by the issuing entity.
The Trustee’s report on an assessment of compliance with the servicing criteria applicable to it during the Issuing Entity’s
fiscal year ending December 31, 2017 and an attestation report by a registered independent public accounting firm regarding the
Trustee’s related report on assessment are attached as exhibits to this Form 10-K.



Except as disclosed below, neither the report
on assessment nor the related attestation report has identified anyadditional material instances of noncompliance with the servicing
criteria described in the report on assessment as being applicable to the Trustee. With respect to the exception identified below,
the Trustee has identified one instance of noncompliance related to the STRATS Trust for Allstate Corporation Securities, Series
2006-3.



Exception:



The Trustee’s report on assessment
and the related attestation report have identified material noncompliance with one servicing criterion applicable to the Trustee:



| | ● | Servicing criterion 1122(d)(3)(i)(A) contemplates that
reports to investors, including those to be filed with the Commission, are maintained in accordance with timeframes and other
terms set forth in the transaction agreements.
| | - | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Noncompliance: During the
period, certain reports to investors were not prepared in accordance with the timeframes set forth in the transaction agreements.
These reports contain the information that is also reported on the EDGAR on Form 10-D Distribution Statement.



Remediation: The Trustee
indicates the reports were delivered outside the timeframe set forth in the transaction agreements. Management has enhanced controls
in order to better ensure reports are delivered timely to investors. Reports filed on EDGAR on Form 10-D were filed timely and
as required.



Item 1123 of Regulation AB. Servicer Compliance Statement.



The Trustee has provided a compliance statement,
signed by an authorized officer, attached as an exhibit to this Form 10-K.



PART IV



Item 15. Exhibits, Financial Statement Schedules.



(a)           List
of Documents Filed as Part of this Report



(1)       Not
Applicable.



4







(2)       Not
Applicable.



(3)       See
Item 15 (b), below.



(b)           Exhibits
Required by Item 601 of Regulation S-K.



| | 31.1 | Rule 13a-14/15d-14 Certification (Section 302 Certification).
| | ---- | -------------------------------------------------------------



| | 33.1 | Report on Assessment of Compliance with Applicable Servicing Criteria of The Bank of New York Mellon for the year ended December
31, 2017.
| | ---- | ------------------------------------------------------------------------------------------------------------------------------------------



| | 34.1 | Independent Accountants’ Attestation Report concerning servicing activities of The Bank of New York Mellon for the year
ended December 31, 2017.
| | ---- | ------------------------------------------------------------------------------------------------------------------------------------------------



| | 35.1 | Compliance Statement of The Bank of New York Mellon for the year ended December 31, 2017.
| | ---- | -----------------------------------------------------------------------------------------



(c)           Omitted.



5







SIGNATURES



Pursuant to the requirements of Section
13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.



|                      | Synthetic Fixed-Income Securities, Inc.

(Depositor)
|--------------------- | ----------------------------------------------------
|                      |                                                     
|Dated: March 30, 2018 | By:                                                 
|                      |                                                     
|                      |                                                     
|                      |                                                     



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EXHIBIT INDEX



|EXHIBIT | DESCRIPTION                                                                                                                                     
|------- | ------------------------------------------------------------------------------------------------------------------------------------------------
|        |                                                                                                                                                 
|31.1    | Rule 13a-14/15d-14 Certification (Section 302 Certification).                                                                                   
|        |                                                                                                                                                 
|33.1    | Report on Assessment of Compliance with Applicable Servicing Criteria of The Bank of New York Mellon for the year ended December 31, 2017.      
|        |                                                                                                                                                 
|34.1    | Independent Accountants’ Attestation Report concerning servicing activities of The Bank of New York Mellon for the year ended December 31, 2017.
|        |                                                                                                                                                 
|35.1    | Servicer Compliance Statement of The Bank of New York Mellon for the year ended December 31, 2017.                                              



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